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Email Template Builder

Email Template Builder

$ npx promptcreek add email-template-builder

Auto-detects your installed agents and installs the skill to each one.

What This Skill Does

This skill builds complete transactional email systems, including React Email templates, provider integration, and a preview server. It supports i18n, dark mode, spam optimization, and analytics tracking. It's ideal for engineering teams setting up or migrating transactional email infrastructure.

When to Use

  • Set up transactional email for a new product.
  • Migrate from a legacy email system.
  • Add new email types (invoice, digest, notification).
  • Debug email deliverability issues.
  • Implement i18n for email templates.
  • Optimize email templates for spam scores.

Key Features

Builds React Email templates.
Supports MJML templates for email client compatibility.
Integrates with multiple email providers.
Provides a local preview server with hot reload.
Supports i18n/localization with typed translation keys.
Offers spam score optimization checklist.

Installation

Run in your project directory:
$ npx promptcreek add email-template-builder

Auto-detects your installed agents (Claude Code, Cursor, Codex, etc.) and installs the skill to each one.

View Full Skill Content

Email Template Builder

Tier: POWERFUL

Category: Engineering Team

Domain: Transactional Email / Communications Infrastructure


Overview

Build complete transactional email systems: React Email templates, provider integration, preview server, i18n support, dark mode, spam optimization, and analytics tracking. Output production-ready code for Resend, Postmark, SendGrid, or AWS SES.


Core Capabilities

  • React Email templates (welcome, verification, password reset, invoice, notification, digest)
  • MJML templates for maximum email client compatibility
  • Multi-provider support with unified sending interface
  • Local preview server with hot reload
  • i18n/localization with typed translation keys
  • Dark mode support using media queries
  • Spam score optimization checklist
  • Open/click tracking with UTM parameters

When to Use

  • Setting up transactional email for a new product
  • Migrating from a legacy email system
  • Adding new email types (invoice, digest, notification)
  • Debugging email deliverability issues
  • Implementing i18n for email templates

Project Structure

emails/

├── components/

│ ├── layout/

│ │ ├── email-layout.tsx # Base layout with brand header/footer

│ │ └── email-button.tsx # CTA button component

│ ├── partials/

│ │ ├── header.tsx

│ │ └── footer.tsx

├── templates/

│ ├── welcome.tsx

│ ├── verify-email.tsx

│ ├── password-reset.tsx

│ ├── invoice.tsx

│ ├── notification.tsx

│ └── weekly-digest.tsx

├── lib/

│ ├── send.ts # Unified send function

│ ├── providers/

│ │ ├── resend.ts

│ │ ├── postmark.ts

│ │ └── ses.ts

│ └── tracking.ts # UTM + analytics

├── i18n/

│ ├── en.ts

│ └── de.ts

└── preview/ # Dev preview server

└── server.ts


Base Email Layout

// emails/components/layout/email-layout.tsx

import {

Body, Container, Head, Html, Img, Preview, Section, Text, Hr, Font

} from "@react-email/components"

interface EmailLayoutProps {

preview: string

children: React.ReactNode

}

export function EmailLayout({ preview, children }: EmailLayoutProps) {

return (

<Html lang="en">

<Head>

<Font

fontFamily="Inter"

fallbackFontFamily="Arial"

webFont={{ url: "https://fonts.gstatic.com/s/inter/v13/UcCO3FwrK3iLTeHuS_nVMrMxCp50SjIw2boKoduKmMEVuLyfAZ9hiJ-Ek-_EeA.woff2", format: "woff2" }}

fontWeight={400}

fontStyle="normal"

/>

{/ Dark mode styles /}

<style>{

@media (prefers-color-scheme: dark) {

.email-body { background-color: #0f0f0f !important; }

.email-container { background-color: #1a1a1a !important; }

.email-text { color: #e5e5e5 !important; }

.email-heading { color: #ffffff !important; }

.email-divider { border-color: #333333 !important; }

}

}</style>

</Head>

<Preview>{preview}</Preview>

<Body className="email-body" style={styles.body}>

<Container className="email-container" style={styles.container}>

{/ Header /}

<Section style={styles.header}>

<Img src="https://yourapp.com/logo.png" width={120} height={40} alt="MyApp" />

</Section>

{/ Content /}

<Section style={styles.content}>

{children}

</Section>

{/ Footer /}

<Hr style={styles.divider} />

<Section style={styles.footer}>

<Text style={styles.footerText}>

MyApp Inc. · 123 Main St · San Francisco, CA 94105

</Text>

<Text style={styles.footerText}>

<a href="{{unsubscribe_url}}" style={styles.link}>Unsubscribe</a>

{" · "}

<a href="https://yourapp.com/privacy" style={styles.link}>Privacy Policy</a>

</Text>

</Section>

</Container>

</Body>

</Html>

)

}

const styles = {

body: { backgroundColor: "#f5f5f5", fontFamily: "Inter, Arial, sans-serif" },

container: { maxWidth: "600px", margin: "0 auto", backgroundColor: "#ffffff", borderRadius: "8px", overflow: "hidden" },

header: { padding: "24px 32px", borderBottom: "1px solid #e5e5e5" },

content: { padding: "32px" },

divider: { borderColor: "#e5e5e5", margin: "0 32px" },

footer: { padding: "24px 32px" },

footerText: { fontSize: "12px", color: "#6b7280", textAlign: "center" as const, margin: "4px 0" },

link: { color: "#6b7280", textDecoration: "underline" },

}


Welcome Email

// emails/templates/welcome.tsx

import { Button, Heading, Text } from "@react-email/components"

import { EmailLayout } from "../components/layout/email-layout"

interface WelcomeEmailProps {

name: "string"

confirmUrl: string

trialDays?: number

}

export function WelcomeEmail({ name, confirmUrl, trialDays = 14 }: WelcomeEmailProps) {

return (

<EmailLayout preview={Welcome to MyApp, ${name}! Confirm your email to get started.}>

<Heading style={styles.h1}>Welcome to MyApp, {name}!</Heading>

<Text style={styles.text}>

We're excited to have you on board. You've got {trialDays} days to explore everything MyApp has to offer — no credit card required.

</Text>

<Text style={styles.text}>

First, confirm your email address to activate your account:

</Text>

<Button href={confirmUrl} style={styles.button}>

Confirm Email Address

</Button>

<Text style={styles.hint}>

Button not working? Copy and paste this link into your browser:

<br />

<a href={confirmUrl} style={styles.link}>{confirmUrl}</a>

</Text>

<Text style={styles.text}>

Once confirmed, you can:

</Text>

<ul style={styles.list}>

<li>Connect your first project in 2 minutes</li>

<li>Invite your team (free for up to 3 members)</li>

<li>Set up Slack notifications</li>

</ul>

</EmailLayout>

)

}

export default WelcomeEmail

const styles = {

h1: { fontSize: "28px", fontWeight: "700", color: "#111827", margin: "0 0 16px" },

text: { fontSize: "16px", lineHeight: "1.6", color: "#374151", margin: "0 0 16px" },

button: { backgroundColor: "#4f46e5", color: "#ffffff", borderRadius: "6px", fontSize: "16px", fontWeight: "600", padding: "12px 24px", textDecoration: "none", display: "inline-block", margin: "8px 0 24px" },

hint: { fontSize: "13px", color: "#6b7280" },

link: { color: "#4f46e5" },

list: { fontSize: "16px", lineHeight: "1.8", color: "#374151", paddingLeft: "20px" },

}


Invoice Email

// emails/templates/invoice.tsx

import { Row, Column, Section, Heading, Text, Hr, Button } from "@react-email/components"

import { EmailLayout } from "../components/layout/email-layout"

interface InvoiceItem { description: string; amount: number }

interface InvoiceEmailProps {

name: "string"

invoiceNumber: string

invoiceDate: string

dueDate: string

items: InvoiceItem[]

total: number

currency: string

downloadUrl: string

}

export function InvoiceEmail({ name, invoiceNumber, invoiceDate, dueDate, items, total, currency = "USD", downloadUrl }: InvoiceEmailProps) {

const formatter = new Intl.NumberFormat("en-US", { style: "currency", currency })

return (

<EmailLayout preview={Invoice ${invoiceNumber} - ${formatter.format(total / 100)}}>

<Heading style={styles.h1}>Invoice #{invoiceNumber}</Heading>

<Text style={styles.text}>Hi {name},</Text>

<Text style={styles.text}>Here's your invoice from MyApp. Thank you for your continued support.</Text>

{/ Invoice Meta /}

<Section style={styles.metaBox}>

<Row>

<Column><Text style={styles.metaLabel}>Invoice Date</Text><Text style={styles.metaValue}>{invoiceDate}</Text></Column>

<Column><Text style={styles.metaLabel}>Due Date</Text><Text style={styles.metaValue}>{dueDate}</Text></Column>

<Column><Text style={styles.metaLabel}>Amount Due</Text><Text style={styles.metaValueLarge}>{formatter.format(total / 100)}</Text></Column>

</Row>

</Section>

{/ Line Items /}

<Section style={styles.table}>

<Row style={styles.tableHeader}>

<Column><Text style={styles.tableHeaderText}>Description</Text></Column>

<Column><Text style={{ ...styles.tableHeaderText, textAlign: "right" }}>Amount</Text></Column>

</Row>

{items.map((item, i) => (

<Row key={i} style={i % 2 === 0 ? styles.tableRowEven : styles.tableRowOdd}>

<Column><Text style={styles.tableCell}>{item.description}</Text></Column>

<Column><Text style={{ ...styles.tableCell, textAlign: "right" }}>{formatter.format(item.amount / 100)}</Text></Column>

</Row>

))}

<Hr style={styles.divider} />

<Row>

<Column><Text style={styles.totalLabel}>Total</Text></Column>

<Column><Text style={styles.totalValue}>{formatter.format(total / 100)}</Text></Column>

</Row>

</Section>

<Button href={downloadUrl} style={styles.button}>Download PDF Invoice</Button>

</EmailLayout>

)

}

export default InvoiceEmail

const styles = {

h1: { fontSize: "24px", fontWeight: "700", color: "#111827", margin: "0 0 16px" },

text: { fontSize: "15px", lineHeight: "1.6", color: "#374151", margin: "0 0 12px" },

metaBox: { backgroundColor: "#f9fafb", borderRadius: "8px", padding: "16px", margin: "16px 0" },

metaLabel: { fontSize: "12px", color: "#6b7280", fontWeight: "600", textTransform: "uppercase" as const, margin: "0 0 4px" },

metaValue: { fontSize: "14px", color: "#111827", margin: 0 },

metaValueLarge: { fontSize: "20px", fontWeight: "700", color: "#4f46e5", margin: 0 },

table: { width: "100%", margin: "16px 0" },

tableHeader: { backgroundColor: "#f3f4f6", borderRadius: "4px" },

tableHeaderText: { fontSize: "12px", fontWeight: "600", color: "#374151", padding: "8px 12px", textTransform: "uppercase" as const },

tableRowEven: { backgroundColor: "#ffffff" },

tableRowOdd: { backgroundColor: "#f9fafb" },

tableCell: { fontSize: "14px", color: "#374151", padding: "10px 12px" },

divider: { borderColor: "#e5e5e5", margin: "8px 0" },

totalLabel: { fontSize: "16px", fontWeight: "700", color: "#111827", padding: "8px 12px" },

totalValue: { fontSize: "16px", fontWeight: "700", color: "#111827", textAlign: "right" as const, padding: "8px 12px" },

button: { backgroundColor: "#4f46e5", color: "#fff", borderRadius: "6px", padding: "12px 24px", fontSize: "15px", fontWeight: "600", textDecoration: "none" },

}


Unified Send Function

// emails/lib/send.ts

import { Resend } from "resend"

import { render } from "@react-email/render"

import { WelcomeEmail } from "../templates/welcome"

import { InvoiceEmail } from "../templates/invoice"

import { addTrackingParams } from "./tracking"

const resend = new Resend(process.env.RESEND_API_KEY)

type EmailPayload =

| { type: "welcome"; props: Parameters<typeof WelcomeEmail>[0] }

| { type: "invoice"; props: Parameters<typeof InvoiceEmail>[0] }

export async function sendEmail(to: string, payload: EmailPayload) {

const templates = {

welcome: { component: WelcomeEmail, subject: "Welcome to MyApp — confirm your email" },

invoice: { component: InvoiceEmail, subject: Invoice from MyApp },

}

const template = templates[payload.type]

const html = render(template.component(payload.props as any))

const trackedHtml = addTrackingParams(html, { campaign: payload.type })

const result = await resend.emails.send({

from: "MyApp <hello@yourapp.com>",

to,

subject: template.subject,

html: trackedHtml,

tags: [{ name: "email-type", value: payload.type }],

})

return result

}


Preview Server Setup

// package.json scripts

{

"scripts": {

"email:dev": "email dev --dir emails/templates --port 3001",

"email:build": "email export --dir emails/templates --outDir emails/out"

}

}

// Run: npm run email:dev

// Opens: http://localhost:3001

// Shows all templates with live preview and hot reload


i18n Support

// emails/i18n/en.ts

export const en = {

welcome: {

preview: (name: "string-welcome-to-myapp-name"

heading: (name: "string-welcome-to-myapp-name"

body: (days: number) => You've got ${days} days to explore everything.,

cta: "Confirm Email Address",

},

}

// emails/i18n/de.ts

export const de = {

welcome: {

preview: (name: "string-willkommen-bei-myapp-name"

heading: (name: "string-willkommen-bei-myapp-name"

body: (days: number) => Du hast ${days} Tage Zeit, alles zu erkunden.,

cta: "E-Mail-Adresse bestätigen",

},

}

// Usage in template

import { en, de } from "../i18n"

const t = locale === "de" ? de : en


Spam Score Optimization Checklist

  • [ ] Sender domain has SPF, DKIM, and DMARC records configured
  • [ ] From address uses your own domain (not gmail.com/hotmail.com)
  • [ ] Subject line under 50 characters, no ALL CAPS, no "FREE!!!"
  • [ ] Text-to-image ratio: at least 60% text
  • [ ] Plain text version included alongside HTML
  • [ ] Unsubscribe link in every marketing email (CAN-SPAM, GDPR)
  • [ ] No URL shorteners — use full branded links
  • [ ] No red-flag words: "guarantee", "no risk", "limited time offer" in subject
  • [ ] Single CTA per email — no 5 different buttons
  • [ ] Image alt text on every image
  • [ ] HTML validates — no broken tags
  • [ ] Test with Mail-Tester.com before first send (target: 9+/10)

Analytics Tracking

// emails/lib/tracking.ts

interface TrackingParams {

campaign: string

medium?: string

source?: string

}

export function addTrackingParams(html: string, params: TrackingParams): string {

const utmString = new URLSearchParams({

utm_source: params.source ?? "email",

utm_medium: params.medium ?? "transactional",

utm_campaign: params.campaign,

}).toString()

// Add UTM params to all links in the email

return html.replace(/href="(https?:\/\/[^"]+)"/g, (match, url) => {

const separator = url.includes("?") ? "&" : "?"

return href="${url}${separator}${utmString}"

})

}


Common Pitfalls

  • Inline styles required — most email clients strip styles; React Email handles this
  • Max width 600px — anything wider breaks on Gmail mobile
  • No flexbox/grid — use and from react-email, not CSS grid
  • Dark mode media queries — must use !important to override inline styles
  • Missing plain text — all major providers have a plain text field; always populate it
  • Transactional vs marketing — use separate sending domains/IPs to protect deliverability
0Installs
0Views

Supported Agents

Claude CodeCursorCodexGemini CLIAiderWindsurfOpenClaw

Details

License
MIT
Source
seeded
Published
3/17/2026

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